Flocked endodontic files and other flocked devices

ABSTRACT

The invention generally provides flocked files for debriding root canals during endodontic procedures. The flocked files comprise a shank with a periphery surface and fibers that are flocked or otherwise attached to the periphery surface. The periphery surface comprises at least one flocked surface segment over which the fibers are dispersed and may include at least one abrading surface segment that is suitable for abrading or scraping the walls of the root canal. The fibers may be composed of various materials and may comprise various textures, Deniers, lengths, and flexibility. The fibers abrade and loosen potential irritants in the root canal architecture, including the recessed regions and the accessory canals, without requiring unnecessary reshaping and removal of dentin from the root canal. The fibers also capture and carry loosened debris out from the root canal.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part of copending U.S.application Ser. No. 09/946,128, filed Sep. 4, 2001. For purposes ofdisclosure, the foregoing application is incorporated herein byreference.

BACKGROUND OF THE INVENTION

[0002] 1. The Field of the Invention

[0003] The present invention relates to the field of dental instruments.In particular, the present invention relates to endodontic files thatare used for debriding and cleaning root canals during endodonticprocedures. Even more particularly, the present invention relates toflocked endodontic files that are used to remove pulp, necrotic tissue,organic debris, and other potential irritants from root canals inpreparation for receiving dental filling materials.

[0004] 2. The Relevant Technology

[0005] Endodontics is the branch of dentistry that generally deals withinfections and diseases of dental pulp. Dental pulp, which is found inthe pulp chamber and root canals of the tooth, comprises a vasculartissue that is generally composed of nerve fibers and blood vessels thatnourish the tooth during its growth and development. When bacteria gainsaccess to the pulp, either through a fractured tooth or a deep cavity,the pulp becomes infected and will die unless the body is able to repairand heal the pulp. Pulp can also become infected when the tooth suffersfrom trauma or a periodontal disease.

[0006] When the pulp becomes so severely infected or otherwise damagedthat it cannot be healed, it is necessary to remove the pulp to relievethe pain and to prevent infection from spreading beyond the tooth. Pulpcan either be removed by extracting the tooth or by performing anendodontic procedure, such as a root canal.

[0007] During a root canal procedure, the endodontist accesses the rootcanal and debrides the root canal of potential irritants such asnecrotic tissue, pulp, bacteria, bacterial byproducts and other debris.Debridement essentially consists of loosening the potential irritantsfrom the sides of the root canal with an endodontic tool, such as afile, and then flushing the potential irritants out of the root canalwith an irrigant. Some irrigants may comprise or are used in combinationwith antibacterial disinfectants and/or chelators to sanitize the rootcanal and to dissolve remaining debris.

[0008] The final step of performing the root canal procedure, which isknown as obturation, involves filling the root canal with a fillingmaterial such as gutta percha or amalgam and sealing the filling with asealer cement to prevent future contamination of the root canal.

[0009] One problem with existing methods and devices for performingendodontic procedures, however, is that the anatomy of the tooth makesit impossible to completely clean potential irritants out of the rootcanal. In particular, the root canal is irregularly shaped, havingcontoured surfaces, recessed regions and accessory canals. The irregularshape of the root canal prevents existing endodontic files from reachingand abrading the entire surface area of the root canal, thereby leavingportions of live, diseased or necrotic pulp and debris undisturbed.

[0010] Some existing flexible endodontic files are capable of followingthe irregular contours of the perimeter surfaces of the root canal.However, even these existing flexible files are unable to completelyreach and abrade the recessed regions and accessory canals of the rootcanal. Accordingly, to provide access to the hard-to-reach regions ofthe root canal, it is often necessary to “reshape” or file down thewalls of the root canal. This however, is undesirable because it cancause overthinning of the root canal which increases the risk that anendodontic tool, such as a file or an irrigation cannula, will fractureor perforate the walls of the root canal, causing pain to the patientand further complicating the endodontic procedure.

[0011] Reshaping is sometimes required to widen narrow passages of theroot canal in order to access apical regions and to minimize hydraulicpressures during obturation. However, filing down the walls of the rootcanal unnecessarily, simply to provide access to recessed regions fordebridement is undesirable, not only because it increases the risksassociated with overthinning, but also because it increases the time,and hence the cost, associated with performing the root canal.Furthermore, even after reshaping the root canal, existing endodonticfiles are still sometimes unable to adequately reach and abrade therecessed regions and accessory canals.

[0012] Accordingly, there is currently a need in the art for improvedendodontic files for debriding root canals during endodontic procedures.

SUMMARY OF THE INVENTION

[0013] The present invention is directed to improved endodontic filesused to debride root canals during endodontic procedures. The improvedendodontic files of the invention comprise flocked files for abradingand removing pulp, necrotic tissue, organic debris, and other potentialirritants from the root canal structures, including the recessed regionsand the accessory canals.

[0014] Each of the flocked files of the invention comprises a shank witha periphery surface, and fibers that are flocked or otherwise attachedto the periphery surface. In one preferred embodiment, the peripherysurface comprises at least one abrading surface segment with edges thatare suitable for abrading or filing the walls of the root canal and atleast one flocked surface segment over which multiple fibers aredispersed.

[0015] The edges of the abrading surface can be formed in any suitablemanner, such as, for example, by machining the periphery surface, bytwisting the shank, or by depositing abrasive materials such as diamond,ceramic, and metallic particles on the periphery surface. When the edgesof the abrading surface are scraped against the walls of the root canalthe potential irritants on the walls are loosened. With sufficientscraping by the abrading surface, the walls of the root canal can alsobe reshaped or filed down.

[0016] The flocked surface segment of the flocked file comprisesmultiple fibers that are also useful for scrubbing and abrading the rootcanal surfaces. The flocked surface segment may be separated from oroverlap the abrading surface segment and may comprise a singlecontinuous flocked surface segment or multiple separated flocked surfacesegments.

[0017] The fibers disposed on the flocked surface segment(s) assist inthe debridement of the root canal and are particularly useful forreaching and abrading the hard-to-reach areas, such as the recessedregions and the accessory canals, without requiring unnecessaryreshaping and removal of dentin from the root canal. The fibers may becomposed of various plastics, metals, ceramics, or any combinationthereof. Suitable plastics include, but are not limited to,polypropylene, polyethylene, nylon and polyester. Suitable metalsinclude, but are not limited to, tungsten, titanium, titanium alloys,stainless steel, other types of steel, copper, copper alloys (e.g.,brass and bronze), aluminum alloys, nickel and nickel alloys. Suitableceramics include, but are not limited to, carbon (e.g., graphite) andboron fibers.

[0018] The fibers may comprise a uniform length or varying lengths witha preferred length within the range from about 0.3 mm to about 3 mm, andmore preferably within a range from about 0.7 mm to about 1.5 mm. Thediameters of the fibers may also vary, preferably within a range fromabout 1 Denier to about 15 Denier, and more preferably within a rangefrom about 1.5 Denier to about 10 Denier. It will be appreciated thatthe length and diameter of the fibers, as well as the texture,flexibility and the density of distribution of the fibers may vary toaccommodate different needs and preferences.

[0019] The fibers can be attached to the flocked surface segment by anysuitable process, such as electrostatic flocking, injection molding, andwelding. In one preferred embodiment, the fibers are electrostaticallyflocked onto the flocked file segment and secured by an adhesive. Theadhesive in the preferred embodiment is a flexible and water insolubleadhesive, such as a polyurethane or flexible acrylic adhesive. Flexibleadhesives are particularly useful when the fibers are stiff or rigidbecause it allows the fibers to bend at their points of affixation. Itshould be appreciated, however, that other adhesives such as epoxies andsilicones can also be used.

[0020] In some embodiments, the flocked files of the invention alsocomprise a handle and a tip. The tip may be configured for scraping orcutting, or alternatively, the tip may be blunt. The handle is used tomanipulate and move the flocked file within the root canal.

[0021] When the flocked file is rotated or moved up and down within theroot canal, the fibers brush against and loosen the pulp, necrotictissue, organic debris, and other potential irritants in the root canal.The fibers of the flocked file are able to loosen the potentialirritants in the recessed regions and accessory canals more effectivelythan existing prior art endodontic files, without requiring unnecessaryreshaping of the root canal. The fibers are also useful for carrying theloosened debris out from the root canal, for evenly distributingsolutions, and for reducing hydraulic pressures by rupturing trapped airpockets.

[0022] In one alternative embodiment of the invention, the peripherysurface does not include an abrasive surface segment. Rather, accordingto this alternative embodiment, the fibers provide the entire utility ofabrading and loosening the pulp, necrotic tissue, organic debris, andother potential irritants in the root canal. In such an embodiment,rigid fibers are preferred. However, it should be appreciated that theflocked file may comprise any combination of rigid and flexible fibers.

[0023] One skilled in the art will appreciate that flocked files of thepresent invention are an improvement over the prior art for at leastproviding a means for reaching, abrading, and loosening the potentialirritants in the root canal more effectively than existing files withoutrequiring unnecessary reshaping and overthinning of the root canal. Theflocked files of the invention are also an improvement over the priorart files for at least providing fibers to assist in the removal of theloosened debris from the root canal.

[0024] These and other benefits, features and advantages of the flockedfiles of the present invention will become more fully apparent from thefollowing description and appended claims, or may be learned bypracticing the invention as set forth below.

[0025] These and other advantages and features of the present inventionwill become more fully apparent from the following description andappended claims, or may be learned by the practice of the invention asset forth hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] A more extensive description of the present invention, includingthe above-recited features and advantages, will be rendered withreference to the specific embodiments that are illustrated in theappended drawings. Because these drawings depict only exemplaryembodiments, the drawings should not be construed as imposing anylimitation on the present invention's scope. As such, the presentinvention will be described and explained with additional specificityand detail through use of the accompanying drawings in which:

[0027]FIG. 1 illustrates a cross-sectional side view of a tooth with aprior art file inserted into the root canal of the tooth;

[0028]FIG. 2 illustrates one embodiment of the flocked file of thepresent invention in which the flocked file comprises a cylindricalshank and a periphery surface that includes a flocked surface segmenthaving multiple fibers disposed thereon and an abrasive surface segmentthat is formed by machining the shank;

[0029]FIG. 3 illustrates one embodiment of the flocked file of thepresent invention in which the flocked file comprises an angular shank,a handle, and a periphery surface that includes a flocked surfacesegment having multiple fibers disposed thereon and an abrasive surfacesegment that is formed by twisting the shank;

[0030]FIG. 4 illustrates one embodiment of the flocked file of thepresent invention in which the flocked file comprises a cylindricalshank, a handle, a stop, and a periphery surface that includes a flockedsurface segment having multiple fibers disposed thereon and an abrasivesurface segment that is formed by depositing an abrasive material on theperiphery surface;

[0031]FIG. 5 illustrates one embodiment of the flocked file of thepresent invention in which the flocked file comprises a cylindricalshank, a handle, a stop, and a periphery surface that includes multipleflocked surface segments having multiple fibers disposed thereon andmultiple abrasive surface segments separating the multiple flockedsurface segments;

[0032]FIG. 6 illustrates a cross-sectional side view of a tooth with aflocked file of FIG. 5 inserted within the root canal of the tooth.

[0033]FIG. 7 illustrates one embodiment of the flocked file of thepresent invention in which the flocked file comprises a shank, a handle,a tip, and a periphery surface that includes a flocked surface segmentextending substantially from the tip to the handle with multiple fibersdisposed thereon; and

[0034]FIG. 8 illustrates a cross-sectional side view of a tooth with aflocked file of FIG. 7 inserted within the root canal of the tooth.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] The present invention relates to improved endodontic files usedto debride root canals during endodontic procedures. More particularly,the present invention relates to flocked files for removing pulp,necrotic tissue, organic debris, and other potential irritants from rootcanals during endodontic procedures.

[0036]FIG. 1 illustrates a cross-sectional side view of a tooth 10 withan existing prior art file 12 inserted into a root canal 14 a of thetooth 10. As shown, the tooth 10 comprises a crown 16 and two roots 14 aand 14 b. The crown 16 is made of enamel and is generally exposed to theinside of the mouth. The roots 18 a and 18 b are not exposed, butrather, they are embedded within the gingivae (e.g., gum tissue), whichis not shown. The tooth 10 also comprises a pulp chamber 20, and tworoot canals 14 a and 14 b. Each of the root canals 14 a and 14 b extendfrom the pulp chamber 20 to an apex 22 a and 22 b where the root canals14 a and 14 b are supplied by the mandibular canal (not shown). Thetooth 10 also comprises dentin 24, a bone-like material that supportsthe enamel crown 16. Although tooth 10 is depicted as having two rootsand two root canals, it should be appreciated that a tooth may compriseonly a single root and a single corresponding root canal.

[0037] The pulp chamber 20 and each of the root canals 14 a and 14 b aretypically filled with pulp 26. However, in FIG. 1 most of the pulp 26has been removed as part of an endodontic procedure, which is describedbelow. Pulp generally comprises vascular tissue composed of nerve fibersand blood vessels that are essential to the nourishment of the tooth 10during its growth and development. When bacteria gains access to thepulp 26, the pulp 26 becomes infected and will die unless the body isable to repair and heal the pulp 26. When the pulp 26 becomes soseverely infected or otherwise damaged that it cannot be healed, it isnecessary to remove the pulp 26. One method for removing the pulp 26 isto perform the endodontic procedure commonly known as a root canal.

[0038] In performing the root canal procedure, such as on root canal 14a, the endodontist drills a hole 30 through the dentin 24 to access thepulp chamber 20 and the infected root canal 14 a. The endodontist thenuses an endodontic tool, such as file 12 to clean the pulp and otherpotential irritants out from the root canal 18. One problem withexisting files, however, is that they are unable to adequately debridethe root canal 14 a of potential irritants. In particular, the rootcanal 14 a comprises multiple recessed regions 40 and accessory canals50 that line the root canal 14 a. Each of these hard to reach areas maycontain pulp, necrotic tissue, and other potential irritants that needto be removed, but cannot be reached by existing files. Accordingly,even after cleaning the root canal 18 with a file, potential irritantsmay still reside inside of the root canal 14 a. Therefore, it issometimes required to reshape or widen the root canal 14 a to provideaccess to the recessed regions 40 and accessory canals 50. However, withreshaping there is a risk of overthinning the walls of the root 18 a,thereby increasing the probability that an endodontic tool will punctureor rupture the cementum seal 60 encasing the root 18 a, thereby causingpain to the patient and further complicating the endodontic procedure.Furthermore, even after reshaping the root canal 14 a, some hard toreach areas may still be out of reach.

[0039] The flocked files of the present invention minimize the risksassociated with reshaping the root canal 14 a by providing flockedfibers that are able to reach and abrade the recessed regions 40 andaccessory canals 50 more effectively than is currently possible with theprior art files, without requiring unnecessary reshaping andoverthinning of the root canal 14 a.

[0040]FIG. 2 shows one embodiment of a flocked file 70 of the invention.As shown, the flocked file 70 comprises a shank 72 that includes aperiphery surface 74 and multiple fibers 76 that are flocked orotherwise attached to the periphery surface 74. The periphery surface 74comprises at least one abrading surface segment 78 with edges that aresuitable for abrading or scraping the walls of the root canal and atleast one flocked surface segment 80 over which the multiple fibers 76are disposed. When the edges of the abrading surface segment 78 arescraped against the walls of the root canal the potential irritants onthe walls of the root canal are loosened and/or dislodged so that theycan be removed by irrigation or carried out on the multiple fibers 76.The abrading surface segment 78 is also useful for reshaping the rootcanal when required. For instance, with sufficient scraping by the edgesof the abrading surface segment 78, the walls of the root canal can befiled down to a desired shape.

[0041] According to one present embodiment, the edges of the abradingsurface segment 78 are formed by machining or forging grooves into theperiphery surface 74. It should be appreciated, however, that the edgescan also be formed by other suitable processes. For example, the edgesof the abrading surface segment can also be formed by twisting anangular blank, such as a rectangular blank or a triangular blank untilthe edges are twisted into a desired configuration that is suitable forscraping against the surfaces of the root canal. The flocked file shownin FIG. 3, illustrates such an embodiment in which the edges of theabrading surface segment 78 are formed by twisting rectangular blank 82.The shank of the endodontic files according to the invention may includeany suitable material, including but not limited to, metals, ceramicsand the like. Preferred metals include, but are not limited to, nickelalloys (e.g., nickel-titanium alloys), stainless steel, other steels,titanium alloys, tungsten alloys, and high purity tungsten (>99.5%pure).

[0042] In another embodiment, shown in FIG. 4, the edges of the abradingsurface segment 78 of the periphery surface 74 may comprise the edges ofan abrasive material that is deposited on the abrasive surface segment78. Suitable abrasive materials include, but are not limited to,diamond, ceramic, and metallic particles and powders. The abrasivematerial may be secured to the abrading surface segment 78 with anysuitable adhesive, such as epoxy, or with any suitable process, such aswelding.

[0043] As shown in FIGS. 2-4, the flocked files of the inventioncomprise a flocked file segment 80 over which multiple fibers 76 aredisposed. The multiple fibers 76 are particularly useful for brushingand abrading the hard to reach areas of the root canal, such as therecessed regions and accessory canals, which cannot be reached by theabrading surface segment 78. The fibers 76 are also useful for applyingsolutions, such as irrigants, to the root canal. In particular, thefibers 76 can brush the solutions onto the surfaces of the root canalwhile at the same time disrupting the formation of air bubbles and airpockets. It will be appreciated that this minimizes the hydraulicpressures that are created when the solution is introduced into the rootcanal while at the same time enabling the solution to be evenlydistributed over the entire surface area of the root canal. It will beappreciated that some irrigants may comprise or are used in combinationwith antibacterial disinfectants and/or chelators to sanitize the rootcanal and to dissolve remaining debris, such as compositions thatinclude sodium hypochlorite.

[0044] The fibers 76 may be composed of various plastics, metals,ceramics or any combination thereof. Suitable plastics include, but arenot limited to, polypropylene, polyethylene, nylon and polyester.Suitable metals include, but are not limited to, tungsten alloys,tungsten (e.g., high purity tungsten (>99.5% pure)), titanium, titaniumalloys, stainless steel, other types of steel, copper, copper alloys(such as brass and bronze), aluminum alloys, nickel and nickel alloys.Suitable ceramics include, but are not limited to, carbon (such asgraphite) and boron.

[0045] The fibers 76 may also comprise various cut lengths, which may beuniform or vary. According to one preferred embodiment, the cut lengthof the fibers 76 is within the range from about 0.3 mm to about 3 mm,and more preferably within a range from about 0.7 mm to about 1.5 mm.The diameters of the fibers 76 may also vary, preferably within a rangefrom about 1 Denier to about 15 Denier, and more preferably within arange from about 1.5 Denier to about 10 Denier. The texture, flexibilityand the density of distribution of the fibers 76 on the flocked surfacesegment 80 may also vary to accommodate different needs and preferences.

[0046] The fibers 76 can be attached to the flocked surface segment 80by any suitable process, such as electrostatic flocking, injectionmolding, and welding. In one preferred embodiment, the fibers areelectrostatically flocked onto the flocked file segment 80 a and securedby an adhesive. The adhesive in the preferred embodiment is a flexibleand water insoluble adhesive, such as a polyurethane or flexible acrylicadhesive. Flexible adhesives are particularly useful when the fibers arestiff or rigid because it allows the fibers to bend at the point ofaffixation. It should be appreciated, however, that other adhesives suchas epoxies and silicones may also be used, and the adhesives maycomprise various physical properties to accommodate different needs andpreferences.

[0047] As shown in FIG. 3, the flocked files of the invention may alsocomprise a handle 84 and a tip 86. The tip 86 may be configured forscraping or cutting, or alternatively, the tip 86 may be blunt, asshown. The handle 84 is used to manipulate and move the flocked file 70within the root canal. When a handle 84 is included, it may also bedesirable to use a hand piece for facilitating movement of the flockedfile 70, such as the hand piece disclosed in U.S. patent applicationSer. No. 09/425,849, entitled “Systems for Incrementally Adjusting theWorking Length of Endodontic Instruments” and U.S. patent applicationSer. No. 09/425,857, entitled “Incrementally Adjustable EndodonticInstruments,” both of which were filed on Oct. 22, 1999 and areincorporated herein by reference. It will be appreciated, however, thatit is not necessary that the flocked files of the invention comprise ahandle, as illustrated by FIG. 2. Without a handle, it is still possibleto manipulate and move the flocked file 70 within the root canal byholding the shank 72 with fingers, pliers, or another tool.

[0048] As shown in FIG. 4, the flocked files of the invention may alsocomprise a stop 88 to abut against the crown of the tooth and to keepthe tip of the flocked file 70 from penetrating too far into the rootcanal and for working on only predetermined portions of the root canalat a time. U.S. patent application Ser. No. 09/536,821, entitled“Endodontic Systems and Methods for the Anatomical Sectional andProgressive Corono-Apical Preparation of Root Canals With InstrumentsUsing Stops,” filed Mar. 27, 2000, and which is incorporated herein byreference, describes various other endodontic files with stops that canbe combined with the teachings of the present invention.

[0049]FIG. 5 illustrates another embodiment of the flocked file of theinvention. In this embodiment, the flocked file 70 comprises multipleflocked surface segments 80 and multiple abrading surface segments 78.This embodiment is particularly useful for simultaneously brushing andabrading multiple areas of the root canal while providing areas alongthe flocked file 70 for capturing and retaining dislodged debris, aswill be shown and described in reference to FIG. 6.

[0050]FIG. 6 illustrates the flocked file 70 of FIG. 5 inserted within aroot canal 14. As shown, the flocked file 70 comprises multiple flockedsurface segments 80 and multiple abrading surface segments 78. Theabrading surface segments 78 can abrade the majority of the root canal14 when they are manipulated against the surfaces of the root canal.However, the abrading surface segments 78, cannot reach and abrade thepulp and other potential irritants that are located within the recessedregions 40 and accessory canals 50. It will be appreciated that this isthe same problem faced by existing files. To overcome this problem, theflocked files of the invention provide fibers 76 that are able to reachand abrade the surfaces of the root canal 14, even in the recessedregions 40, as shown in FIG. 6.

[0051] The fibers 76 are also able to extend into the accessory canals50 when the flocked surface segments 80 are manipulated against thesurfaces of the root canal 14. Accordingly, by rotating and moving theflocked file up and down within the root canal, the flocked files of theinvention are able to clean the root canal 14 of potential irritantsmore effectively than is possible with existing endodontic files, andwithout requiring unnecessary reshaping and overthinning of the rootcanal 14. If reshaping of the root canal is required, however, theflocked file 70 of the present embodiment can be firmly pressed againstthe surfaces of the root canal. This will cause the fibers 76 to bendand will allow the edges of the abrading surface 78 to scrape againstand reshape the surfaces of the root canal 14.

[0052] Another benefit of the present embodiment is for facilitating theremoval of potential irritants from the root canal. In particular, theprofiles of the abrading surface segments 78 are recessed from thefibers 76 and are suitable for receiving dislodged debris 90 so that itcan be pushed up and out of the root canal 14 by the fibers 76. Thefibers 76 also facilitate the removal of debris 90 by capturing andholding the debris 90 between the fibers 76 until it is pulled out ofthe root canal 14.

[0053] Yet another benefit of the flocked files of the invention is thatthe fibers 76 urge the flocked files towards the center of the rootcanal 14. This is a benefit because it minimizes the risk of ‘ledging.’Ledging occurs when a practitioner attempts to insert an endodontic tooldown to the apex 22 of the root canal 14 and the tip of the endodontictool is halted prematurely against the sidewall of the root canal 14.The downward pressure exerted on the tool can cause the tip to dig intothe side of the root canal and form a ledge. Such ledges are difficultto bypass, and if the ledge occurs very close to the apex 22, the ledgemay give the practitioner the mistaken impression that the apex 22 hasbeen reached.

[0054] Turning now to FIG. 7, one alternative embodiment of theinvention is shown. In this embodiment, the periphery surface 74 doesnot include an abrasive surface segment. Rather, according to thisalternative embodiment, the periphery surface 74 only includes a flockedfiber segment 80 with fibers 76 that are configured to be abrasiveenough that they alone provide the entire utility of abrading andloosening the pulp, necrotic tissue, organic debris, and other potentialirritants in the root canal. In such an embodiment, rigid fibers arepreferred. However, it should be appreciated that the flocked file 70may also comprise any combination of rigid and flexible fibers 76.

[0055]FIG. 8 illustrates one implementation of the flocked file of FIG.7. As shown, the fibers 76 are distributed over the entire flocked filesegment 80 and the flocked file 70 is inserted within the root canal 14.According to this embodiment, the fibers 76 of the flocked file 70comprise both very short rigid fibers composed of a metal, such astitanium, and longer more flexible fibers composed of a plastic, such asnylon.

[0056] The short rigid fibers provide a suitable abrasive for scrapingand debriding the easy to reach areas of the root canal 14 and whenrequired, they can also be used to reshape and file down the surfaces ofthe root canal 14. In some circumstances it is desirable that the shortrigid fibers are somewhat flexible so that they can move in and aroundthe irregularities of the root canal 14. In these circumstances theshort rigid fibers are affixed to the flocked file 70 with a flexibleadhesive that allows the short rigid fibers to bend at their points ofaffixation without eliminating the abrasive quality of the fibers. Thelonger more flexible fibers are long enough and flexible enough to reachand abrade the hard to reach areas of the root canal, such as theaccessory canals 50.

[0057] Accordingly, one skilled in the art should appreciate thatflocked files of the present invention are an improvement over the priorart for at least providing a means for reaching, abrading, and removingthe potential irritants from the root canal without requiringunnecessary reshaping and overthinning of the root canal. The flockedfiles of the invention are also beneficial for minimizing the risks ofledging and for facilitating the application of solutions to the rootcanal while minimizing hydraulic pressures created by trapped airpockets.

[0058] Although specific detail has been provided regarding variousembodiments of the flocked files of the invention, it should beappreciated that the present invention may be embodied in other formswithout departing from its spirit or essential characteristics. Forexample, it should be appreciated that the fibers disposed on theflocked files of the invention may comprise various compositions,lengths, textures, flexibilities, diameters, and densities ofdistributions. The fibers may also be disposed in any desiredconfiguration on the flocked file, whether evenly, unevenly, or inpatterns. The abrading surface segments and the flocked surface segmentsmay also be configured in any desired configuration. For example, asshown in FIG. 3, the flocked surface segment 80 may overlap the abradingsurface segment 78. Furthermore, there may also be portions of theperiphery surface that comprises neither an abrading surface segment,nor a flocked surface segment.

[0059] Accordingly, as properly understood, the preceding description ofspecific embodiments is illustrative only and in no way restrictive. Thescope of the invention is, therefore, indicated by the appended claimsas follows.

What is claimed and desired to be secured by United States LettersPatent is:
 1. An endodontic file comprising: a shank having a proximalend opposite a distal end; and a periphery surface extending from theproximal end to the distal end, the periphery surface comprising: anabrading surface segment comprising edges configured for abrading a wallof a root canal in a tooth; and a flocked surface segment comprising aplurality of fibers disposed thereon.
 2. An endodontic file as definedin claim 1, wherein the shank comprises at least one of a metal orceramic.
 3. An endodontic file as defined in claim 1, wherein the shankcomprises at least one metal selected from the group consisting ofnickel alloys, nickel-titanium alloys, stainless steel, other steels,titanium alloys, tungsten alloys, and tungsten that is at least 99.5%pure.
 4. An endodontic file as defined in claim 1, wherein the fiberscomprise at least one of a plastic, metal or ceramic.
 5. An endodonticfile as defined in claim 4, wherein the fibers comprise at least oneplastic selected from the group consisting of polypropylene,polyethylene, nylon and polyester.
 6. An endodontic file as defined inclaim 1, wherein the fibers comprise at least one metal selected fromthe group consisting of tungsten alloys, tungsten that is at least 99.5%pure, titanium, titanium alloys, stainless steel, other types of steel,copper, copper alloys, brass, bronze, aluminum, aluminum alloys, nickel,and nickel alloys.
 7. An endodontic file as defined in claim 1, whereinthe fibers comprise at least one ceramic selected from the groupconsisting of carbon, graphite, and boron.
 8. An endodontic file asdefined in claim 1, wherein the fibers are attached to the peripherysurface by means of a water insoluble adhesive.
 9. An endodontic file asdefined in claim 1, wherein the fibers are attached to the peripherysurface by means of electrostatic flocking.
 10. An endodontic file asdefined in claim 1, wherein the flocked surface segment overlaps atleast a portion of the abrading surface segment.
 11. An endodontic fileas defined in claim 1, wherein the abrading surface segment comprises atleast one edge configured for scraping or filing.
 12. An endodontic fileas defined in claim 11, wherein the shank is an angular shank andwherein the at least one edge is formed by twisting at least a portionof the shank.
 13. An endodontic file as defined in claim 11, wherein theat least one edge is formed by machining at least a portion theperiphery surface.
 14. An endodontic file as defined in claim 11,wherein the at least one edge comprises an abrasive material that isdeposited on at least a portion of the periphery surface.
 15. Anendodontic file as defined in claim 1, wherein the file furthercomprises a handle fixedly attached to the proximal end of the shank.16. An endodontic file as defined in claim 15, wherein the file furthercomprises a tip located at the distal end of the shank, and wherein theflocked surface segment is located proximate the tip.
 17. An endodonticfile as defined in claim 1, wherein the file comprises multiple flockedsurface segments, each of said multiple flocked surface segments beingseparated by portions of the abrading surface segment.
 18. An endodonticfile comprising: a flexible shank having a proximal end opposite adistal end, the shank tapering from the proximal end to the distal end;a periphery surface extending from the proximal end to the distal end; asurface segment located on the periphery surface; and fibers disposed onthe flocked surface segment, said fibers comprising a mixture of rigidfibers and flexible fibers, the flexible fibers being longer than therigid fibers.
 19. An endodontic file as defined in claim 18, wherein thefibers comprise at least one of plastic, metal or ceramic.
 20. Anendodontic file as defined in claim 18, wherein the fibers have a lengthin a range of about 0.3 mm to about 3 mm.
 21. An endodontic file asdefined in claim 18, wherein the flocked surface segment covers theentire periphery surface.
 22. An endodontic file comprising: a flexibleshank having a proximal end opposite a distal end; and a peripherysurface extending from the proximal end to the distal end, the peripherysurface comprising: multiple abrading surface segments each, comprisingedges configured for abrading a wall of a root canal in a tooth; andmultiple flocked surface segments, each of said flocked surface segmentscomprising fibers disposed thereon.
 23. An endodontic file as defined inclaim 22, wherein at least one of the multiple flocked surface segmentsoverlaps at least a portion of at least one of the abrading surfacesegments.
 24. An endodontic file as defined in claim 22, wherein saidmultiple fibers comprise at least one of plastic, metal or ceramic.